People with lupus may develop Antiphospholipid Syndrome (APS), a condition that can cause blood clots and other health problems. APS is sometimes called Antiphospholipid Antibody Syndrome.

What is APS? 

Everyone makes antibodies — certain proteins in blood that fight off illness. But if you have lupus, you may also have antibodies that attack healthy cells and tissues. Some people with lupus make antibodies called antiphospholipid antibodies. 

Many people with antiphospholipid antibodies will not have any complications. But some people will have blood clots inside the blood vessels or pregnancy complications.  APS happens when these complications occur. 

Blood clot complications can include:

• Stroke (blocked blood flow to the brain that causes brain cells to die)
• Heart attack (blocked blood flow to the heart that causes heart muscle to die)
• Pulmonary embolism (blocked blood flow to the lungs that causes lung tissue to die) 

Not everyone with antiphospholipid antibodies will have pregnancy complications. But some people may have pregnancy complications that can include:

• Miscarriage (a loss of a pregnancy before 20 weeks of pregnancy) 
• Stillbirth (a loss of a baby after 20 weeks of pregnancy)
• Pre-eclampsia  (a condition that develops in pregnant women with high blood pressure and the presence of protein in the urine)

Learn more information about lupus and pregnancy.

How do doctors diagnose APS? 

Your doctor will do blood tests to check for antiphospholipid antibodies and to see if your blood is clotting normally. 

Your doctor will also ask questions about your medical history to find out if you’ve had these APS-related problems:

• Blood clots 
• Low blood platelets (thrombocytopenia)
• Miscarriages or other pregnancy complications

What’s the treatment for APS? 

If you have been diagnosed with APS, and you have had a blood clot, you will need to take medicines to prevent blood clots, also called blood-thinning medications.  The most commonly recommended medications include:

• Warfarin (Coumadin®) pills
• Heparin injections

What about the new oral medications to prevent clots – direct oral anti-coagulants (DOACs)?

The limited studies show that oral (by mouth) anti-coagulant medications are not as effective as warfarin in preventing clots.  At this time the evidence suggests that warfarin or heparin is necessary to prevent clots. 

Are there other medications that I should take as a lupus patient with APS?

Data suggest that in addition to blood thinners, people with lupus and APS should take:

• Low dose aspirin (also called baby aspirin)
• Hydroxychloroquine 

What if I have these antibodies and have never had a clot or pregnancy complications?

Your doctor may recommend that you take:

• Low dose aspirin (also called baby aspirin)
• Hydroxychloroquine 

Can I take APS medicines during pregnancy? 

Some blood thinners, like warfarin (Coumadin®), aren’t safe to take when you’re pregnant. If you’re pregnant or trying to get pregnant, talk with your doctor about treatment options that are safe for you and your baby. 

• If you haven’t had pregnancy complications or clot in the past, your doctor may recommend low-dose aspirin
• If you’ve had miscarriages or other pregnancy problems in the past, or you have had a blood clot, your doctor will recommend heparin injections in addition to low-dose aspirin

What else can I do to prevent blood clots?

You can take these steps to lower your risk of blood clots:

• If you smoke, make a plan to quit 
• Stay at a healthy weight by eating a healthy diet and getting regular physical activity

Some types of birth control and hormone replacement therapy (HRT) medicines can increase your risk of blood clots. If you have APS and you take hormonal birth control or HRT, your doctor may recommend that you stop or change these medicines to prevent clots. Learn more about lupus and birth control.

What are the symptoms of blood clots?

Learn the signs of blood clots so you can get help when you need it. 

If you have blood clots, you may notice these symptoms in your arms or legs:

• Throbbing or cramping pain
• Swelling
• Redness
• Heat

If a blood clot moves to your lungs, you may notice:

• Trouble breathing or shortness of breath
• Sharp chest pain that gets worse when you breathe in
• Coughing that brings up blood

If you have any of these symptoms, get medical help right away. Be sure to let the doctor know that you have APS.